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Heat Transfer 175

Figure 10-104. Kettle reboiler—estimate of shell diameter. Example: If the vapor rate is 50,000 lb/hr and the bundle is 25 ft, then V/L is 2,000
lb/(hr)(ft). Entering the curve at this V/L ratio, with an operating pressure of 50 psia and a bundle diameter of 24 in. gives an estimate for shell
I.D. of 40 in. (Used by permission: Palen, J. W., and Small, W. M. Hydrocarbon Processing, V. 43, No. 11, ©1964. Gulf Publishing Company, Hous-
ton, Texas. All rights reserved.)

1
U 112 (10-161)
1 A o A o 1 A o Note that h 1 must be assumed to solve this equation and
r w c d r i c d c d
h 1 A Avg A i h i A i later verified. An iteration on h 1 will possibly result in a bal-
ance.
where
For a single tube:
U (1) single tube overall heat transfer coefficient
h 1 nucleate boiling coefficient for single tube, outside
0.69 0.31 0.33
Btu/hr (ft) (°F) U 1 T LM C L 144Pk L L
h 1 0.225C s c d c d c 1d (10-162)
2
h i heating side film coefficient, Btu/(hr) (ft ) (°F) v